Methods and processes to provide proper hygiene and microbial control are essential in modern meat processing plants. Current automated processing plants place increased demands on processing equipment and cleaning procedures to ensure that microbial control is maintained throughout the process in order to prevent contamination of large amounts of processed meat. In the poultry industry, bacterial control is particularly important because of the propensity of poultry to harbor pathogenic bacteria such as Salmonella spp., Enterobacter spp., Campylobacter spp. and Escherichia coli.
A typical poultry processing plant will generally be divided into two related processing stages. In the first stage, poultry processing steps include transporting, hanging, stunning, bleeding, scalding, defeathering and beheading. The bacterial load in this stage is generally high. Furthermore, the likelihood of cross contamination is very high during this stage because of the large numbers of bacteria brought into the process during slaughtering and defeathering. Common contact points of the poultry, such as scalding before defeathering, also present likely points of cross-contamination.
After the feathers and heads are removed, the poultry enters the second stage of the process which includes removing viscera, separating carcass and organs, washing, chilling, draining, packaging and shipping. Even though the bacterial loads in the second stage are typically not as high as in the first stage, this stage also requires careful bacterial control to ensure that no contamination or cross-contamination occurs in any of the processing steps and that the poultry is not contaminated when packaged and shipped.
A variety of materials and methods have been used to control bacterial contamination during poultry processing. For example, different antimicrobial agents or materials, including antibiotic compounds, have been used during the scalding and washing steps. At the present time, however, the use of antibiotic compounds to treat poultry is not approved by the Food and Drug Administration or U.S.D.A. and only sodium hypochlorite solutions, irradiation or trisodium phosphate solutions (See, e.g., U.S. Pat. Nos. 5,069,922 and 5,143,739 that report contacting defeathered and eviscerated poultry with a solution containing trisodium phosphate) are approved disinfectant treatments for poultry.
Alternative materials and processes, in addition to the approved treatments, have been reported. U.S. Pat. No. 5,093,140 reports adding a mixture of two or more lower molecular weight organic acids and a surfactant to the scalding or washing water. U.S. Pat. No. 4,849,237 reports sanitizing poultry carcasses with ozonated water. U.S. Pat. No. 4,770,884 reports contacting poultry carcasses with an acidic solution containing an anionic sulfate or sulphonate surfactant. U.S. Pat. No. 4,766,646 reports a method of disinfecting poultry carcasses by dipping the carcass in a solution containing acid polyformate salts.
Other known sanitizing agents or antibacterial materials include organic acids, hydrogen peroxide solutions, glutaraldehyde and other chemical or antibiotic compounds. See, e.g., Cunningham, Chapter 9--Methods of Preservation of Poultry Products, The Microbiology of Poultry Meat Products, Academic Press, 275-292 (1987). Testing of various organic acids indicate that concentrations of at least 2.0-5.0 wt. % are required. At these concentrations the organic acids are caustic and are not considered to be acceptable. More specifically, at these concentrations the organic acids cause severe discoloration to the skin and meat of the processed poultry.
The many different types of agents and materials that have been used to disinfect processed poultry clearly indicate that there is no generally accepted disinfectant agent or material for use on poultry. Essentially all of the agents or materials referred to above involve balancing desirable benefits against undesired effects. Specifically, any useful agent or material must have an effective antimicrobial activity against known pathogenic organisms but must not change or alter the texture, color, taste, odor or appearance of the poultry. In addition, the agent or material must be safe to use on a food product and should be easy to handle and use as well as being environmentally compatible and easy to dispose of or replace as needed. The stringent requirements needed to provide a suitable disinfecting product and process have prevented the acceptance of a generally recognized method for controlling or reducing bacterial contamination of processed poultry.